Mycobacterial Infections in Patients Treated with Tumor Necrosis Factor Antagonists in South Korea

The aims of this study were to determine the incidence of tuberculosis (TB) and nontuberculous mycobacteria (NTM) lung disease in patients who were treated with tumor necrosis factor (TNF) antagonists in South Korea and to evaluate their clinical characteristics. We surveyed all patients (N = 509) who were treated with TNF antagonists at Severance Hospital, South Korea, between January 2002 and December 2011. We reviewed the patients' medical records and collected microbiological, radiographic, and clinical data, including the type of TNF blocker(s) used and the results of tuberculin skin tests and interferon-gamma release assays. Rheumatoid arthritis (43.6 %) and ankylosing spondylitis (27.9 %) were the most common diseases in the patients treated with TNF antagonists. Patients received etanercept (33.4 %), infliximab (23.4 %), or adalimumab (13.2 %). The remaining patients received two or more TNF antagonists (30 %). Nine patients developed TB, and four patients developed NTM lung disease. After adjustment for age and sex, the standardized TB incidence ratio was 6.4 [95 % CI 3.1-11.7] compared with the general population. The estimated NTM incidence rate was 230.7 per 100,000 patients per year. Our results show that mycobacterial infections increase in patients treated with TNF antagonists. The identification of additional predictors of TB for the treatment of latent tuberculosis infection and the careful monitoring and timely diagnosis of NTM-related lung disease are needed for patients who receive long-term therapy with TNF antagonists.